On 03/27/2018 10:02 AM, Tejun Heo wrote:

Hello,

On Mon, Mar 26, 2018 at 04:28:49PM -0400, Waiman Long wrote:

quoted

Maybe we can have a different root level flag, say,
sched_partition_domain that is equivalent to !sched_load_balnace.
However, I am still not sure if we should enforce that no task should be
in the root cgroup when the flag is set.

Tejun and Peter, what are your thoughts on this?

I haven't looked into the other issues too much but we for sure cannot
empty the root cgroup.

Thanks.

Now, I have a different idea. How about we add a special root-only knob,
say, "cpuset.cpus.isolated" that contains the list of CPUs that are
still owned by root, but not participated in load balancing. All the
tasks in the root are load-balanced among the remaining CPUs.

A child can then be created that hold some or all the CPUs in the
isolated set. It will then have a separate root domain if load balancing
is on, or an isolated cpuset if load balancing is off.

Will that idea work?

Cheers,
Longman